U.S. Publication No. 2008/0293592 describes a method for covalently immobilizing probe-biomolecules on organic surfaces by means of photoreactive cross-linking agents. The method has in practice proven to be advantageous particularly because it permits an immobilization of probe biomolecules on unreactive surfaces, such as silanized glass supports and substrates made of standard commercial plastics. A polymer is used in the method described in US 2008/0293592 to form a type of three-dimensional network onto which the probe biomolecules can be bonded, either at the network's surface or in the inside of the network. Compared to an organic surface on which the probe biomolecules are only immobilized in two-dimensional form, the three-dimensional immobilization of the biomolecules in the polymer and/or copolymer network permits a higher density of the probe biomolecules on the organic surface. This increases the amount of analyte which can be bonded per surface unit of the organic surface. Use of the surface as biological sensor thus gives rise to a higher measurement accuracy and a high measurement dynamic.
However, a disadvantage of the methods and polymer networks described in U.S. 2008/0293592 is that analyte molecules or analyte components which bind to probe biomolecules arranged on or close to the surface of the polymer network can block the network. Further analyte molecules or analyte constituents can then no longer bind as well to as yet unbound probe biomolecules which are arranged at a greater distance from the surface of the network in its interior.
Thus, there is a need for improved polymer networks.